Warm air furnace



Jan. 23, 1934. i| A, BERTOSSA 1,944,488

WARM AIR FURNACE gmc/Wto@ u s k V) #ary/Z. Berta ssl` Jan.`23, 1934. H,A, BERTossA 1,944,488

WARM AIR FURNACE Filed OOC. 24, 1932 2 Sheets-Sheet 2 me/who@ v /arzyBert ossa @Wma/13.0

Patented Jan. 23, 1934 PATENT OFFICE WARM AIR FURNACE Harry A. Bertossa,Detroit, Mich., assigner of one-half to James Rodney Weeks, Birmingham,

Mich.

Application October 24, 1932. Serial No. 639,339

, 13 Claims.

This invention relates generally to heating apparatus and refers moreparticularly to warm air furnaces. n

One of the essential objects of the invention is to provide a furnace ofthis type wherein a combustion chamber is enclosed within an outer shellor casing and is provided with a fire box, a dome portion'and adepending flue portion.

Another object is to provide a furnace wherein 1o the outer shell orcasing has a base portion provided at one side with an inlet for air andhas avdome portion that tapers upwardly from the base portion andsupports a mixingchamber kfor heated air.

Another object is to provide a furnaceY wherein the fire box has adownwardlytapering ash pit portion supported uponsuitable legs above thelower Vend of the casing so that air. from the inlet may flow beneathand around the same. Another object is to provide a furnace wherein thedome'portion ofthe combustion chamber cooperates with upright walls ofthe casing to provide restricted passages for air and 'tapers upwardlywithin and at a slightly different in-` clination than thefupwardlytapering dome portion of the casing so that upwardly flaring passagesfor air are provided therebetween.

Another object is to provide a furnace wherein means, preferably in theform of tubes, extend upwardly through the upwardly tapering dome of thecombustion chamber in substantially parallel relation to the inclinedwalls thereof from points just below the restricted passages aforesaid.35 V Another object is to provide a furnace wherein a ue extendingupwardly in the casing constitutes an outlet for smoke from thedepending iiue portion of the combustion chamber and a heat radiatingmember for the air circulating within the casing. 1 Y y A Another objectis to provide a furnace wherein the rear horizontal portion of thecombustion chamber and casing is constructed in such a way relative tothe flue just mentioned that the flue and horizontal portion may bereadily cleaned and kept free of sediment.l Y Another object is toprovide a furnace wherein the opposed walls of the re box and dependingflue portion of the combustion chamber are connected by a wall'of thedome portion that supports certain of the tubes extending upwardlythrough the dome portion and in addition to affording added heatradiating surfaces for the 55 air in the space therebetween cause suchair to be directed to the lower ends of the tubes sup-v ported bysaidwall of the dome portion.

Another object is to provide a furnace wherein the opposed walls of there box and depending ue are arranged in such a way that oil used as fuelwithin the fire box will be eec-V tively prevented from passing directlyvinto the flue.

Another object is to provide a furnace wherein means accessible from thefront of the casing is provided for controlling the flow of air upwardly4 uponl opposite sides of the combustion chamber.

Other objects, advantages and novel details of construction of thisinvention will be marde more apparent as this description proceeds,especially when considered in connectionwith the accompanying drawings,wherein:

Figure 1 is a vertical transverse sectional view through a furnaceembodying my invention taken on the line l-1 of Figure 2; 75 Figure 2 isa vertical longitudinal sectional view;

Figure 3 is a sectional view taken on the "line 3--3 of Figure 2; j j

Figure 4 is a sectional View taken on the line 4-4 of Figure 2. j

Referring now to the drawings, A is the casing or jacket; Bis the mixingchamber; VC is the blower or propeller, and D isthe combustion chamberof a furnace embodying my invention. As shown, the casing A has a baseor body portion l provided in one side at its lower end with an inlet 2for air from the blower C, and has a dome portion 3 that tapers upwardlyfrom the upright walls of said base portion and supports the mixingchamber`B. The combustion chamber D is located within the casing A andis preferably provided with a fire box 4, a dome portion 5 and adepending flue portion 6. Preferably the fire box has a downwardlytapering ash pit chamber '7 provided with a suitable door 8 andsupported upon suitable legsr9. As shown, a portion 10 of the casing Ais offset inwardly in rear of this door and receives the projecting ends11 of suitable grates 12 rwithin the iire box. A lining 13 of fire brickis preferably provided for the re box. The dome portionV 5 of thecombustion chamber has a slightly different inclination than andterminates just below the upper end of the upwardly tapering domeportion 3 of the casing. Such dome portion 5 also has a tubularprojection 14 extending through the casing A and provided with a door15.

In order that the maximum e'iciency may be obtained the lower end of thedome of the combustion chamber overhangs the upper side v edges of there box 4 and depending flue 6 and cooperates with the upright side walls1d and 1b of the casing base 1 to provide restricted passages 16 and 17respectively for air just below the upwardly tapering dome portions 3and 5. In this connection it will be noted that portions 5a and 5b ofthe dome portion 5 diverge upwardly from the upright side walls 4a and4b respectively of the fire box to points adjacent the upright walls 1aand 1b of the base 1 and then converge upwardly from said points to thetop 5e of said dome portion. Preferably the upwardly converging walls 1cand 1d of the dome portion 3 of the casing cooperate with the convergingportions 5c and 5d of the' dome portion 5 to form air passages 5m and512. which extend upwardly from the restricted passages 16 and 17 to thetop 5e of the dome portion 5. As shown, these passages 5m and 5ugradually increase in cross sectional area from their lower to theirupper ends. Tubes 18 extend Yupwardly through the diverging portions 5aand 5b of therdome 5 yof the combustion chamber in substantiallyparallel relation to the inclined walls 5c and 5d thereof from pointsjust below the restricted passages 16 and 17 to points just above thetop 5e of the dome and are adapted to conduct air from the spaces 19 and20 respectively between the fire box 4 and casing to the mixing chamberB. In this connection it will be noted that the spaces 19 and 20 arerestricted with respect to the space 7a in the casing about thedownwardly tapering ash pit chamber 7; and that the upwardly divergingportions 5a and 5b of the dome will cooperate with the upright walls 1aand 1b of theV casing to direct into the restricted passages 5m and 511.Athe air that is not received within the tubes 18.

In the present instance the smoke outlet comprises a flue 21 thatextends upwardly within the casing A from a horizontal extension 22 ofthe depending flue 6 to an elbow 23 extending laterally outwardlythrough vthe casing. Preferably the outer end 24 of the extension 22serves as a clean-out opening and has a door 25. Thus the flue 6 may bereadily cleaned and kept free of sediment. Moreover, the constructionand arrangement of the portion 6 and flue 21 is such that bothconstitute heat radiating members for the air within the casing. In thisconnection it will also be noted that the opposed walls 26 and 27respectively of the fire box and flue 6 are connected by a wall 28 ofthe dome and that tubes 29 corresponding to the tubes 18 extend upwardlyfrom this wall through the dome portion 5 of the combustion chamber andare adapted to conduct air from the space 3l) between said opposed walls26 and 27 to the mixing chamber B. Thus the opposed walls 26 and 27 andwall 28 not only constitute added heat radiating l surfaces but alsoserve to direct the air to the tubes 29. Moreover, it will be noted thatthe wall 26 extends transversely of the combustion chamber at the rearof the grates 12 consequently such wall will effectively prevent oilwhen used as fuel from passing directly into the flue 6. In

- strips or dampers 3l and 32 respectively are hingedly mounted in thespaces 19'and 20 for controlling the upward flow of air and are operablefrom the front of the casing by suitable handles 33 and 34 respectively.

Thus from the foregoing it will be apparent that I have provided anextremely efficient structure wherein the air from the blower Crwill beforced upwardly around the re box 4 and through and around the dome 5 ofthe combustion chamber to the mixing chamber B from which it may beconducted by any suitable means such as the pipes 35 to the rooms to beheated. Preferably a battle 36 upstanding upon the top 5e of the domeportion 5 throughout its length is provided to divide the air from theconverging upper ends of the inclined tubes 18 so that turbulence willbe prevented. Thus, air from the passages 5m and 57i will rst comminglewith air from the tubes 18 and will then be thoroughly commingled in themixing chamber B before entering the pipes 35. Inasmuch as the ash pitchamber 7 isl spaced above the bottom of the furnace and is tapereddownwardly, the air received in the casing from the blower is adapted tocirculate beneath and around the combustion chamber. In fact, theconstruction is such that the pressure of the air builds up in thebottom of the casing A and such air is in effect squeezed upwardlysubstantially uniformly upon all sides of the combustionv chamberthrough the tubes 18 and 29 and passages 5m and 511.. The taperedformation of the dome portions 3 and 5 is such that the .air in passingtherebetween will be directed in close proximity to the dome portion 5so as to be heated thereby. Moreover the air within the casing A will beheated by the fire box 4 and flue 6, wall 28 and flue 21 with the resultthat the maximum heat absorption is obtained. Preferably the casing Aand combustion chamber D and associated parts are built of steel and alljoints are weldedso that a leak proof and sturdy construction isprovided. In practice the apparatus may be readily installed and anysuitable fuel may be used inv the fire box portion 4 of the combustionchamber.

What I claimv as my invention is:

1. In a furnace, aV casing having a base portion provided with an inletfor air and having an upwardly tapering dome portion, and a combustionchamber within the base portion in spaced relation thereto and having anupwardly tapering dome portion within and spaced from theV dome portionaforesaid of the casing, the lower end of said combustion chamber domeportion cooperating with a portion of the casing to form a restrictedpassage for air, tubes extending through the combustion chamber domeportion from points just below the restricted passage to points justabove the dome portion, and a mixing chamber carried by the dome portionof the casing for receiving air from the restricted passage and fromsaid tubes.

2. In a furnace, a casing having an upwardly converging domeportion, amixing chamberon the'upper end of the dome portion having outlets inopposite sides thereof, a combustion chamber within the casing andhaving an upwardly converging dome portion within the dome portion ofthe casing, means for conducting air from the space between thecombustion chamber and casing through the Vdome portion of thecombustion chamber to the mixing chamber including tubes extendingthrough the dome portion of the combustion chamber and converging at apoint adjacent the upper end of the dome portion of the casing, andmeans upstanding upon iso V11,944,488 i the dome 'portion-of the'combustion' chamber for dividing the 'air from the converging upperrends i of i the tubes `so that turbulence will be' prevented andV suchair will flow' properly through the -mixofthe base'portion to theimixing chamber, a 'i combustion chamber within the casing having'upright side walls substantially parallel to'and Vterminating below theedges of the vertical side `walls of the casing, and having a domeportion `extending upwardly within the dome portion of fthe casing andprovided adjacent the upper end -of the domelportion of the casing with'av top,the

--side2wallsof the doxneportion of the combustion chamber diverging fromthe upper'ends of the 'upright side walls of the' chamber to pointsadjacent to the upright walls of the base and converg- -ing from said.points at a greater angle of'inclination'than the converging walls ofthe dome portion ofthe casing to the top aforesaid, and tubes extendingupwardly through the divergingportions and top aforesaid of the domeportion of the chamber.

4. In a furnace, a combustion chamber having a body portionprovided withupright walls, and "an upwardly tapering vdome portion, the domevportion being provided at its-lower end with porrtions that divergeupwardly from the upright walls 'of the'body portion, and provided atits upper end witha top, tubes for air extending through said nupwardlydiverging'portionsand top, said'tubes 5being close and substantiallyparallel to the sides `of thetapering dome portion, and an outer cas-Iinghaving upright walls substantially'parallel to and extending above`the upright walls Aof the chamber and having'an upwardly tapering dome`portion receiving but 'disposed at a slightly dif- `4ferentVinclination than the `upwardly* tapering i'dome portion of Ythe chamberwhereby the dome f 'portion Iof the casing cooperates with the idoineportion of the combustion chamber to provide 'upwardlyflaring passagesfor air,'the upright 'walls of the casing extending aboveandcooperating'with the upwardly diverging portions of the domeportionof the chamber to form restrictions for air at the lowerends of theupwardly flaring passages just above the llower 'ends 4of "the tubes,whereby portions ofthe air iiowing upwardly between Ithe ,parallelvwalls will be received in the tubes while other portions of said airwill be squeezed through the restrictions aforesaid into the upwardlytapering passages aforesaid.

5. In a furnace, a casing having an upwardly converging dome portion, amixing chamber on the upper end of the dome portion having outlets inopposite sides thereof, a combustion chamber within the casing andhaving an upwardly converging dome portion within the dome portion ofthe casing, means for conducting air from the space between thecombustion chamber and casing through the dome portion of the combustionchamber to the mixing chamber including tubes extending through the domeportion of the combustion chamber and converging at a point adjacent theupper end of the dome portion of the casing.

6. In a furnace, a casing having a body portion, a dome portion, and amixing chamber above the uppermost part of the dome portion,

- the body portion having upright side walls, and

the dome portion tapering upwardly froms'aid side walls, a combustionchamber havingabody *portion within the body portion of the casing'a'ndhaving an upwardly tapering dome portion within the upwardly taperingdome portion of the casing, the top of the body portion Aof the`combustion chamber being below the tapering dome portion of the casing,the dome portion ofthe casingcoyoperating with the dome portion of thechamber :to provide upwardly flaring passages for air, the dome portionof the chamber overhangingthe body -portion of the chamber within thebody -portion of the casingat the lower ends of the upwardly taperingpassages 'for air -and'cooperating with the 'upright side walls of thecasin'gto form restricted passages for air, and tubes for air'extendingvupwardly from points between the body portions of the chamber andcasing just'belowthe restrictedpassages for air through the dome portionof the chamber to points just above 'the 'top of the dome -portion ofthe chamber between and yadjacent to the upwardly aring passages forair, whereby air from said upwardly flaring -passages will comminglewith the air from the tubes and then be thoroughly commingled within`the mixing chamber.

7. In a furnace, a fire box, aV dome aboveland projecting rearwardlybeyond said re box, said projecting portion of the'dome beingprovided'at one side of the rire box with a depending flue portion, theside of said depending portion adjacent the fire box being spaced andinclineddownwardly and away therefrom, and means for conducting airupwardly from the space between the adjacent walls of the re box andflue portion through the dome, including a tube 'extending through theprojecting portion of the dome and through the top thereof, said tubeterminating at the upper end of the space vbetween the adjacent wallsaforesaid. Y.

8. In a furnace, a casing having a clean-out opening, a vertical ue insaid casing just labove said opening, a re box, a dome above andprojecting rearwardly beyond the fire box, said projecting portion ofthe `dome being providedat one side of the fire box with a dependingflue portion, the side of said vdepending portion adjacent the fire boxbeing spaced and inclined downwardly and away therefrom, means forconducting 'air upwardly from the space between the 'adjacent 1 walls ofthe fire box and flue portion through the dome, including a tubeextending through the 'projecting portion of the dome kand through thetop thereof, said tube terminating at the upper` v end of the spacebetween the adjacent walls 130 aforesaid, and a horizontal flue portionprojecting rearwardly from the depending portion to y said clean-outopening and connected to the lower end of the vertical flue.v

9. A furnace having a combustion chamber provided with a dome portion,means cooperating with the dome portion to form passages for conductingair exteriorly of the dome portion from a point below the same to apoint above the uppermost part of said dome portion, and tubes forconducting air interiorly of the dome portion from a point below thesame to a point above the uppermost part of said dome portion, saidpassages and tubes converging upwardly and discharging adjacent eachother substantially in a, common horizontal plane above said domeportion, the exterior passages gradually increasing in cross sectionalarea from their lower to their upper ends.

10. A furnace having a casing, a combustion fchamber Within the casingprovided with a dome portion, means cooperating with the dome por- :tionto form passages for conducting air exteriorly of the dome portion froma point below the same to a point above the uppermost part of -saiddomeportion, said passages gradually in- -creasing in cross sectionalarea fro-m 'their lower to their upper ends, and tubes for conductingair interiorly of the dome portion from a point below the same to apoint above the uppermost part of said dome portion, said passages and-tubes converging upwardly and discharging ad- 'jacent each othersubstantially in a common horizontal plane, adjacent sides of thepassages -and tubes being substantially parallel through- 'out theirlength, vsaid dome portion and casing box having upright wallssubstantially parallel to the upright walls of the body, the domeportion of the combustion chamber being provided at the upper ends ofthe uprightwalls of the -re box with laterally projecting portions thatincline upwardly andoutwardly within the body and terminate adjacent theupright walls thereof, said domeportion of the combustion charnberhaving walls converging upwardly from the supper ends of said laterallyprojecting portions to points adjacent the upper end of the dome portionof the casing, and cooperating with the walls aforesaid thereof toprovide upwardly flaring passages for air, tubes extending upwardly`'through the laterally projecting portions from points between thecombustion chamber and casing through the combustion chamber to pointsabove the uppermost part of the dome portion of the combustion chamber,and means for forcing air under pressure within the casing about thercombustion chamber fire box and upwardly through the tubes and upwardlyflaring passages. f

12. A furnace having a casingprovided at one side in its lower end withan inlet for air and provided at its upper end with a mixing chamber forair, a heating chamber within the casing spaced from the bottom thereofand terminating below the mixing chamber, means for increasing thepressure of air in the inlet aforesaid, a p0rtion of the heating chamberhaving walls c0- operating with the casing to form a chamber in whichair under pressure from the inletl may accumulate, the heating chamberalso having upright walls closely adjacent and cooperating with thecasing to form a restriction for air from the second mentioned. chamber,said heating chamber being provided with outwardly diverging wall.portions above the upright walls cooperating with the casing to furtherrestrict the passage of air, said heating chamber being provided abovethe outwardly diverging Wall portions with upwardly converging wallportions, and the casing having wall portions converging upwardly frompoints adjacent the outwardly di- .verging wall portions aforesaid topoints adjacent the upper ends of the upwardly converging wall portionsof the heating chamber and forming with the heating chamber passagesthat flare upwardly from the outwardly diverging portions aforesaid tothe upper end of. the heating vchamber for discharging air into themixing chamber; x Y

13. Ina furnace, a combustion chamber having a body portion providedwith upright walls, and an upwardly tapering dome portion, the domeportion being provided at its lower end with portions that divergeupwardly from the upright walls of the body portion, and provided at its-upper end with a top, tubes for air extending through said upwardlydiverging portions and top, said tubes being close and'substantiallyparallel to the sides of the tapering dome portion, and an outer casinghavingv upright walls substantially parallel to and extending above theupright walls of the chamber and having an upwardly tapering domeportion receiving and cooperating with the upwardly taperingdome portionof the chamber to form upwardly and inwardly inclined passagesV for air,the upright walls of the casing extending. above and cooperating withthe upwardly diverging portions of the dome portion vof the chamber toform restrictions for air at the lower' ends of rthe upwardly andinwardly inclined passages for air adjacent the lower ends of the tubes,whereby portions of the air flowing upwardly between the parallel wallswill be

